By: Lynn McCain 

As the SARS-CoV-2 virus continues to mutate over time and new booster vaccines become available, the question arises, are the multivalent boosters more effective at improving immune response than the monovalent vaccines with which we began? This question was addressed by a multi-site group from Columbia University Vagelos College of Physicians and Surgeons (New York) and from the University of Michigan Medical School Department of Pathology. Drs. Riccardo Valdez, Carmen Gherasim, and Aubree Gordon represented the Immunity Associated with SARS-CoV-2 (IASO) research team at U-M.

These research teams explored the effectiveness of the original mRNA vaccines when three doses were given followed by a bivalent-booster for the BA.4-BA.5 (omicron) variants. The bivalent booster group was compared to those who received either three or four doses of the monovalent mRNA vaccine and those who received three or four doses of the monovalent mRNA vaccine followed by a breakthrough infection. Pseudo-viral neutralization assays were used to test the neutralizing-antibody titers from each group against the D614G strain (original), as well as against all of the variants and related viruses.

The research study found that boosting with the bivalent mRNA vaccines targeting both the BA.4-BA.5/omicron variants did not result in any discernable improvement in the virus-neutralizing capability of the vaccine as compared to the original monovalent vaccines; however, further studies will continue to explore the potential benefits of bivalent mRNA vaccines.

The study results were published as a letter to the editor on January 11, 2023, edition of The New England Journal of Medicine.  

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Full citation:

Wang Q, Bowen A, Valdez R, Gherasim C, Gordon A, Liu L, Ho DD. Antibody Response to Omicron BA.4-BA.5 Bivalent Booster. N Engl J Med. 2023 Jan 11. doi: 10.1056/NEJMc2213907. Epub ahead of print. PMID: 36630643.